In conventional numerical controllers, with three-dimensional models of a workpiece, jig, tool, machine, or the like available as machine data, a relative position between the workpiece and the tool is controlled to control processing of the workpiece by the tool while performing interference checking.
In interference checking, interference between a three-dimensional model of a workpiece and a three-dimensional model of a tool can be recognized as a cut region and ignorable. Further, a three-dimensional model of a workpiece can be deformed by calculating a cut region according to travel of the three-dimensional model of the tool.
Further, in the numerical control machine tools disclosed in JP 2012-53508 A and JP 2012-53509 A, a three-dimensional shape, position, and orientation of a workpiece fixed to a machine tool can be measured in a non-contact manner.
In order to perform interference checking, three-dimensional models of a tool and a workpiece with a jig are necessary. For a workpiece repeatedly processed, in consideration of possible variation of the shape of the workpiece, it is reliable to measure the actual shape of the workpiece fixed to the machine tool to obtain a three-dimensional model of the workpiece. Further, even with no variety in the shape of the workpiece expected, the position of the jig holding the workpiece may be varied each time the workpiece is processed. Thus, it is reliable to measure the actual shape of the jig fixed to the machine tool to obtain a three-dimensional model of the jig.
Therefore, it is conceivable to create three-dimensional models by measuring the shape of a workpiece and a jig by using a three-dimensional measuring device. However, when creating the three-dimensional models by measuring a workpiece and a jig fixed to a machine tool by using a three-dimensional measuring device, the three-dimensional measuring device cannot determine whether the obtained three-dimensional coordinates represent the measured result of the workpiece or the jig. Therefore, it is impossible to distinguishably provide a three-dimensional model of a workpiece and a three-dimensional model of a jig.
When processing a workpiece while performing interference checking, it is necessary, during a cutting process, to sense interference between a jig and a tool, but it is necessary to ignore interference between the workpiece and the tool. Thus, the three-dimensional model of the workpiece and the three-dimensional model of the jig should be distinguishable.